Stoker



sroxmr" Filed July 7.1922 12 Shuts-Sheet 3 L. R. STOWE 'SToxsR' FiledJuly 1922 12 Sheets-Sheet 4 Mag" 10' 1927.-

L. R. STOWE 12 Sheets-Sheet 5 May I L. R. STOWE STOKER Filed July 7.1922 12 Shoots-Sheet 8 L. R. STOWE May. 10 1927.

STOKER Filed July 7 1922 12 Shesis-Sheet l @QQMN U mNN NNN

5R Stew/8' May10,1927. 1,627,715

L. R. smwe:

STOKER Filed y 7, 1922 Sheets-Sheet l1 May io,1927. 1,627,715

L. R. STOWE STOKER Filed July '7. 1922 12 Sheets-Sheet 12 loyal/ P 19M?- Patented May 10, 1927.

PATENT oFFios.

LOYD n. 'srowii, on ST. LOUIS, 'lviisso'vnr'.

ST'OKER.

Application filed July 7, 1922. Serial 1%. 573,303.

This invention relates to improvements in stok'ers and has for itsobject to provide a new and improved stoker mechanism, in which the coaland other fuel may be proper- 151 advanced to the combustion chamber ofa furnace and the ash resulting from the cornbustion thereott' may beremoved from the stoker proper and collected in a suitable place ofdeposit from which it may intermittently be discharged.

Another object consists in the provision of mechanism to positivelyassist the discharge of ashfrom the grate.

Another object consists in the provision of a structure such as outlinedabove in which the combustion chamber will be securely sealed from theash pit save dur ing short periods of time during which the collectedash is being discharged, my structure being designed to substantiallyprevent ingress of air to the combustion chamber save through the grate,thereby eliminating short circuiting and obtaining olose control of thedraught.

Another object consists in the provision of damper mechanism to controlthe draught adjacent the rear of the grate.

Still another object consists in the provision of new and improvedactuating means for the intermittent actuation of the ash discharge. v II I These and other objects will be more fully set forth and describedin the following specification and shown in the accompanyin'g drawings,in which-- F gure' 1 is a vertical longitudinal section through afurnace showing an embodiment of my invention located therein the gratebeing shown in outline in part and diagrammatically in part;

F 2 is a plan view of the grate showing various eleinen'ts thereofremoved for purpose of illustration, portions of the structure beingalso shown as broken away and other portions in section Fig. 3 is avertical longitudinal section taken along tne line 3--3 of F 2, some ofthe grate links and connecting pins being omitted for clearness and somebeing shown in outline only;

Fig. a is a section similar to Fig. 3 being tas n along the line 4+4: of2;

Fig. 5 is a transverse verticalsection along the line 55 of Fig. 4,showing the kicker actuating means;

Fig. 6 is a section along the line 66 of Fig. 5";

. Fig. 7 is a plan view of a portion of the grate showing one of thegrate chains between adjacent tuyere bars;

Fig. 8 is a transverse section along the line 88 of Fig. 7

Fig. 9 is a longitudinal section along the line 99 of Fig. 7;

Fig. 10 is a similar view along the line 10 of Fig. 7

Fig. 11 is a. plan view of one of therea'r end supporting blocks;

Fig. 12 is a. side elevation of the same;

Fig. 13 is a section along the line 13-13 of Fig. 12;

Fig. 14 is a section along the line 141 l of Fig. 12;

Fig. 15 isa section along the line l5 15 of Fig. 12;

Fig. 16 is a side elevation of one of the sealing aprons;

F 17 is a front elevation of the same;

v Flg. 18 is a bottom plan view of the same, one of the ash divertingplow members being indicated in dotted lines;

19 is a plan view of one of the plows;

I 1* 1g. 20 1s a vertical section along the line 20-20 of Fig-.19;

F 21 is a front elevation of the same;

Fig. 22 is a side elevation of the construction at the inner side of oneof the side frame members, adjacentapron member and transverse channelbeing shown in section, together with the idler sprocket shatt;

Fig. 23 is a vertical section along the line 23-23 or Fig; 22, thesprocket shaft being shown in elevation V i Fig. 24 is a perspective ofaside apron block;

Fig. 25' is a plan view of one of the kicker casings;

Fig. 26 is a side elevation of the same Fig. 27is a section along theline 2727 of Fig. 26;

Fig. 28'is a side elevation of one of the kickers;

Fig.1 29 is an end elevation of the same; Flg. 5301s an end elevation ofthe ash discharge actuating mechanism showing the arrangement of thewater feed pipes;

Fig. 31 is a plan view of the actuating pump;

Fig. 32 is a section along the line 32-32 of Fig. 31;

Fig. 33 is a vertical section along the line 33-33 of Fig. 31; and

Fig. 34: is a similar section along the line 34 34. of Fig. 31.

Like numerals refer to like elements throughout the drawings, in whichdesignates generally a fire or ignition arch, 51 the rear wall of thecombustion chamber, 52 the air chamber beneath the stoker and 53 the ashdischarge chute. Located at the front of the furnace is provided a feedhopper 55, having a constricted discharge passage 55 the size of whichmay be regulated by raising or lowering feed gate 56 by any suitablemechanism. Located in the combustion chamber A is the stolzer generallyindicated by numeral 60, having a downwardly inclined upper surface 61.The grate of the stoker is formed by alternate moving chain portions 60and intermediate tuyere bars 60 which are stationary. The chains are allformed of overlapping link plates 60 connected by means of suitable pins60 and provided with passages 60*. The tuyere bars, as shown in Figs. 7to 9, for example, are formed of a plurality of overlapping jointedplates 60="-, suitably joined together by belts or pins 60, and havingsuitable air passages 60 therethrough.

At the ends of the stoker are provided carrying shafts 65, 66respectively, the sprocket wheels 67 being carried upon the shaft torotate thereon and to mesh with the chains. On the shaft 66 are carriedthe idler wheels 68 partially surrounding which run the chains in aconventional manner. At the sides of the stolrer are provided sideframes, generally indicated by numeral 75, formed in sections. Thesections of the side frame are secured together and supported byconcrete work while the center frames, similar in construction to theside frames, are supported by floor B, pedestals 80, 81, andsub-foundation C. Extending between the side frames are the transversesupporting beams 83, 8 1, 85, 86 and 87, the last being larger and allof the beams being preferably of l-section for the purpose of strength.Extending between and secured to the upper flanges of the i i-beams bybolts 89 or the like, are the tuyere supports 90, shown, for eX- ample,in Figs. 2, 3, 4 and 8 to 1.0. These tuyere supports are constructedwith longitudinal sides 90* between which extend cross-ribs 90 fromwhich project upwardly the lugs 90, preferably tapered at the ends,these lugs being provided to properly guide and aline the chains feedingbetween the central ribs of the chain links in the space provided forsprocket and idler wheels, see Fig. 8 for example. The tuyere supportsare further provided with cross-ribs 90 upon which ride the chains, asshown for example in Figs. 8 to 10, these cross-ribs being slightlyraised above the upper surface of the sides 90" to form shoulders 90 seeFig. 8. In alinement with the ribs 90 and projecting at either side ofthe sides 90 are the spacing l 90. hen the structure is assembled, itwill be apparent, as shown in Fig. 8, that a slightly depressed seat isprovided between shoulders 90 of adjacent supports 90, in which areseated the tuyere bars 60 this construction assuring a proper assemblyof the tuyere bars and preventing their accidental displacement ortoppling, and also eliminating in ordinary constructions the necessitvfor fastening the tuyere bars to the SUPPOILS. At the rear of the stokerin alinementwith the tuyere bars are the supporting blocks 100 shown inFigs. 1-, 11 and 12, for example, each of these blocks being providedwith a forwardly e: tending arm 100 formed of parallel spaced platesfrom which extend laterally at either side, the lugs 100, having theirupper surfaces slightly above the plane of the upper surfaces of theplates 100 to form shoulders 100, spaced apart a distance substantiallyequal to the thickness of the tuyere bars t form a continuation of theseats therefor. Between the plates 100 at the front end thereof, is aconnecting boss 100 which is provided with a bolting aperture 100through which, when in assembled position, extends the bolt 102, seeFig. 4-, which bolts the block 100 to supporting beam 6'4". The bodyportion of the block 100 is slotted at 100 to fit over idler wheel shaft66, a small block 103 being fitted into the slot and secured therein bya bolt 10%, see Fig 1, thereby forming with the block 100 a supplementalsupport for shaft 66. The web 100 of the body of the block 100 is curvedat 100' to accommodate the belt 104, see Figs. 4, 12 and 15. Surroundingthe web 100 is a flange 100*, the bottom of which is enlarged andapertured for insertion of bolts 106, which secure the bloclrs 100 tothe flange of a transverse channel 107. Located upon the upper portionof the flange 100 is the bolting channel 100 to accommodate bolt 108. Aseat 100 is provided at the upper front of the flange .100 for a purposedescribed below. Located below the seat 100 and separated thererom by aportion of flange 100 are the seats 100 formed by a dividing web 100 seeFigs. 12 and 1 1 for example.

Aprons generally indicated by numeral 110 are provided and locatedacross the rear of the grate, to-provide a seal between the combustionchamber and the draught chamber beneath the stoker. These aprons shownfor example in Figs. 2, 4, 16, 17 and 18, are provided with a curvedportion 110, having shallow pockets formed on its outer surface by meansof checker ridges or ribs 110". The aprons 110 are each formed with aforwardly projecting top portion 110, having a downwardly extendingpositioning lug 110 at each side thereof and a downwardly extendingcentrally located lug 110*. The lugs 110 rest upon the correspondingseats of supporting blocks 100, one lug of each adjacent apron 110resting upon the seat 100 of the same supporting block 100, each apronserving to bridge the gap between a pair of adjacent blocks 100. Lecatedat the upper portion of the inner surface of the wall 110 is theforwardly projectin'g, centrally located, locking lug 110 eiiga'geableby the rear end of plow member 150 as indicated in dotted lines in Fig.18. At each side of the curved wall 110 is provided a hemi-con'icaldepression 110 having hemi-cylindrical groove 110 these depressinus andgrooves furnishing, when the aprons are in assembled relation, means forseating" of the bolts 108 with the heads 108 see Fig. 4, each boltserving to partially secure the adjacent apron plates to the subjace-ntsupporting blocks 100. The depressious 108 permitcovering bolt heads 108with cement, or the like, to protect them from the heat. At one side,the wall 1 10 is provided with the extending flange 110 of lessthickness than the wall and. fitting in corresponding recesses 110 inthe adjacent apron plate, thus providing an interfitting relationbetween all of the apron plates. Underlying the curved wall 110 is alsothe strengthening rib' 110 shown in Figs. 16, 17 for example, the sameterminating above the lower end of the apron plates, which lattcrareprovided with depending tail portions 110 underlying which arethespaced ribs 110. lVh-en in assembled relation, as shown in Fig. 4,the ribs 110 contact with channel 107, the tails 110 of the apron plates110 terminating adjacent the shoulder of transverse plate 115, whichextenos across between the side frame members which are supported on theconcrete sub-foundation C, see Fig. 1. It will be understood that insubstantial alinement with each of the tuyere bars is a supporting block100 while the apron plates 110 extend across the entire space betweenthe side frame members. The rear combi'istionchamber wall 51 is offsetat 51 to form an ash chute in conjunction with the aprons 110. At thebottom of the chute 120 is provided a' closure plate 121, pivoted at 122g A fulcrum 123 extends rearwardly from the plate 115 and upon the same'is'pivote'd intermediate its extremities, the lever 124, one

end which is pivotally attached to link 125, the other end of the latterbeing p1voted at 125 to the bottom of plate 121. An

operating rod 126 extends forwardly from lever 12 1 to which it ispivotally connected,

ii-0, is provided a casing 130, see Figs. 25 to At its lower frontportion is an car 130" with bolting aperture 130 the ear being locatedbetween the side plates 100 of the supporting block 100, and bolted orriv- 'eted thereto through apertures 100*, see Fig. 41. Between thesides of the casing 130 is mtiunte'd a kicker having trunni-ons 135, orthe like, journaled in the apertures 130 in the sides of the casing 130.Each of these kickers is provided with a depending lin 135 there being ahole to accommodate a pin 135 therethrough'. The front of the kicker 135is of arcuate form as indicated at 135 to closely fit an inwardlyprojecting top itlai'ige 130 of the casing 130 A lug or sl'ioulder 135is located the end of the arcua-te portion 135 its purpose being tocontact with flange 130 to limit the upward movement of the kicker 135.From each kicker extends a link 136 pivoted to the 1111135 by means ofthe fin 135 at one end, and to the crank arm 13'? at the other, thecrank arms being carried by and rotatable with shaft 138, suitablyjournaled in brackets 139, secured to and projecting from transversebeam 87. A shaft 138 is provided for each group of kickers so that thelatter may be actuated as units, each unit containing any desired numberof kickers,

obv io'us that the more units; there are provided, the more local thetreatment which n'iay be applied to the ash and unburned fuel at therear end of the grate It will be obvious in this construction that akicker is located in alinem'ent with each or the tuye're bars 60", thesekickers serving to disturb or agitate the ash, unburned fuel, clinkers'or the like, which may collect at the end of the tuyeres and assist itsdischarge into chute 120.

Each of the shafts 138 projects through the side frame at one side ofthe stoker and through a passage 139 in the corresponding side wall 139of the furnace, terminating in a chamber 1 10 located beneath the floorlevel. From the shaft 138 at its extremity is provided a rocker arm 1 11to which is pivotally connected one eXtremity of a connecting bar 1 12,which in turn is pivoted at- 1 12 to an operating lever 143, having asocket 1 13 in which is seated an operating handle 1 145. A locking 1111 15 is provided apertured for the insertion of a pin 1 16, which alsoextends through the lever 1&3 when the latter is in inoperativeposition, thus serving to lock the lever in such position. A hollowpedestal 147 surrounds the connecting bars 1 12 and terminates in atableportion located at a desirable height above the floor. It will beobvious that the manipulation of the handle 1 A up and down, willactuate the corresponding unit group of k ckers to agitate and dischargethe ash above said kickers.

Located intermediate the casings 130 are the ash diverting or plowmembers 150, see Figs. to 21 for example, these plow members beingprovided with wedge shaped forwardly projecting portions 150*, havingraised ribs 150" thereon. and the reduced or rearwardly extendingflanges 150 having tapered openings 150 therethrough and shoulders 150being formed by portions 15 and the flanges 150. In the assembly of theplow members 150, they are attached to the aprons 110 by tilting themsufficiently to permit insertion of the flanges 150 beneath the topportions 110 of the aprons, the lugs 110* fitting in the apertures 150and the rear ends of the flanges 150 resting upon the locking lugs 110as shown for eX- axanmle in Fig. 3. The forward portion of each plow 150rests upon the chain 61, plows and chains being of substantiallyidentical width, the latter preventing disengagement of the plows fromthe aprons. The upper surfaces of casings 130 are angled or inclined attheir rear portions to substantially aline with the upper surfaces ofthe plow members 150, this construction aiding in the skidding ofclinker, ash and the like off the grate surface. 0

The side frames are provided throughout the greater portion of theirlength with overhanging, inwardly projecting top portions 175, to whichare secured half tuyere supporting blocks 1'? 6 by means of machinescrews 17?, or the like, see Fig. 5. The overhanging portions 175 of theside frames are cut away as indicated in dotted lines at 175, Fig. 2,for example, and apron blocks 180 are provided resting upon the sideframes and having depending rib portions 180 depending below the uppersurface of the side frames and secured to the latter to form acontinuation thereof. These apron blocks are provided with the inwardlydirected shoulders 180 which contact with the ad jacent plows 150.Bearwardly of the portion 180 is the recess 180 into which projects thelug 180. The adjacent apron plate 110, see Fig. 22, is arranged with thelug 110 fitting between the lug 180 and the shoulder 180 formed at theend of the recess 180. In this manner the overhanging portions 175 ofthe side frames and portions 180 of the blocks 180 contact with theadiaeent chains at the sides of the grate and thereby prevent shortcircuiting of the draught air at the sides of'the grate and the seal atthe end thereof formed by the apron plates extending continuously fromone side to the other of the combustion chamber. The side frame at itsrear portion is provided with the flanged bearing seat 185 whichsupports the end of the idler wheel shaft 66, cross belt 186 maintainingthe shaft in seated position. The side frames are grooved or recessed topermit the dropping of the shait into the seat 185, a large bearingsurface at which is provided by the flanges 185, as shown in Fig. 23,for example. Depending portion 180 of the block 180 also fits in thedepressed portion of the side frame.

It will be apparent that if air chamber 52 is in communication with theoutside atmosphere or with a source of air under pressure, the draughtair is substantially prevented from short circuiting past the sides ofthe stoker and at the rear end thereof, due to the construction abovedescribed. At the front end a plate 200 overlies and rests upon thesurface of the stoker beneath the fuel hopper 55, plate 200 beingreenforced by an additional plate 200 where the fuel is fed upon it. Itwill be apparent that the plate 200, when fuel is present in the hopper55 and restin upon the grate serves to prevent the escape or entrance ofdraft air at the front of the grate.

It is desirable in some instances to regulate the supply of draught tothe rear end of the grate and for that purpose I provide a stationarybaffle 201 secured to the I-beam 86 and depending therefrom. This plate201 rests against one of the rollers 202 which serve to support thereturn runs of the chains. The plate 201 is provided with cut awayportions or port 201" through which the runs of the chain may pass.Located. below the baffle 201 is the shaft 203 extending between thesupporting lugs 204; and pivoted therein. Carried by the shaft 203 arethe brackets 205 to which is secured a damper plate 206 having a pivotedlower flap 206. This damper, in the embodiment shown, is slightly bentor angled, so that when in closed position, as indicated in full linesin Fig. l, the upper portion will rest against the roller 202. and thelower portion with the flap 206 establishes contact with thesubfoundation C. When there is an accumulation of ash, dust or the like,upon the sub-foundation, the flap 206 will ride thereover and serve toform therewith a seal on closing movement. Carried by the upper portionof the damper 206 is a lug 206 to which is pivotally attached the link207, also pivoted at 207 to a rocker shaft 208. An operating rod 209 ispivoted at one end to the rocker 208 and is provided with a handle 209extending outwardly at the front of the furnace for manipulation. Bypulling out the rod 209, the damper 206 may be moved to. positionindicated in dotted lines in Fig. 1, permitting free passage of thedraught air to. the rear end of the grate. Vilhen it is desired toaccentuate the draught through the zone of the greater combustion on thegrate, the damper may beclosed or partially closed thereby substantiallyrestricting the draught to such zone.

The plows 15,0 and kickers and casings 13 5, 130 provide an incline toretard and oppose the passage of the ash and thus serve to thicken thebed of ash, unburned fuel, and the like, at the point of discharge, thisbeing a desirable result. Should the accunnilating ash reach too greatanamount, the kickers 135 may be actuated to assist in its dis-v chargeonto plate 121.

In the handling of the ash and products of combustion, it is desirableto quickly discharge the material deposited upon the ash plate 121 andquickly close the same so that the draught in the furnace may not besubstantially interfered with, and tothat end I have provided anactuating mechanism which will function automatically in cycles coveringa desired period of time, the opening and closing of the ash plate beingrelatively quick, the plate remaining in closed position, during thegreater portion of the cycle in order that the discharge may accumulatethereon.

This mechanism 1' have illustrated in Figs. 30 to 3%. it comprises apair of steam cylinders generally indicated by numerals 225 and 226 andcorresponding pair of hydraulic cylinders 22'? and 228, cylinder 227being in alinement and cooperating with cylinder 225, these twocylinders constituting what 1 term pilot cylinders, cylinder 228 beingin alinement with cylinder and constitutitng therewith what 1 termservice cylinders.

As will be described below, the cylinders 227 and 228 are com reeledwith an available source of fluid, under pressure, such as water fromany available source, cylinders 225 and being connected *ith a source ofstean'i, for example, steam from the boiler l'ieing heated by thefurnace. All of the ct ders are united in a common frame, as shown forexample in Fig. 31, and a common steam chest 230 is provided, to whichsteam is led from any suitable source through the pipe 230, the steamchest being also provided with an exhaust duct 236. Slidabl :mounted insteam. chest 230 is the slid-e valve 231 controlling the admission ofsteam to cylinder 225, an inletduct 225 being proyided leading to theoperating end of cylinder 225 and likewise an exhaust duct- 225" locateda slight distance from the adjacent cylinder head. The piston 2 3,3.

located beneath bearing 240.

reciprocates in cylinder 225 and is carried by piston rod 234 to theother end of which is attached hydraulic piston 235. At its other end,which I term the non-operative end, cylinder 225 is provided with theconstantly open exhaust duct 225 also located a slight distance from theadjacent cylinder end, leading to amain exhaust port 236. The valve rod231 is attached to the slide valve 231 and projects outwardly throughsuitable stuffing box in the steam chest 230, being provided with abifurcated head 231 between which is pivotally attached the rod 238,pivoted at its other end to the depending arm 239 of rocker shaft 239,journal'ed in the pedestal bracket 210. At its opposite end rocker shaft239 carries the actuating arm 239 actuatable in the. manner describedbelow, see Figs. 32 and 33 for example. Carried by the piston rod 23-21is the actuating block 234" operated by which is the actuating arm 241,carried by the rocker shaft 250, jo-urnaled in a bearing 251 At itsopposite end rocker shaft 250 carries the arm 2,50 opposed with respectto the shaft 250. from arm 241. Cylinder 226. is constructed similarlyto cylinder 225 being provided with inlet duct 22,6, duct 226 and;exhaust duct 226. slide valve 231 is provided in valve chest 230 tocontrol the flow of steam to and from cylinder 226 in a similar manner,Valve, rod 260 extends through the stuliing box and to. it isv pivotallyattached a rod 261, pivotally attached at its other end to arm 250 Apiston 2,63 reciprocates in cylinder 226 and carries piston rod 264which is also secured to. hydraulic piston 265 in cyl-e inder 228. Anactuating block 264'?- carried by therod 264 contacts with the end ofactuating arm 239 It will thus, be seen from reference to Figs. 32, 33and 3,4.- that movement of the piston 263, for example, in onedirection. will move the valve 231 in similar direction while movementof the piston 233 in one direction will result in movement of valve 260vin the opposite direction.

Cylinders 2- 5 and 226 are open through exhaust ducts 225 and 226 at thenon-open ative ends of the c linders, while pilot cylinders 225 and 227are open at their ii ends thus providing also non-operative ends. Frompiston 263 leads a second piston rod 126 which may be a continuation ofpiston rod 26-; previously described, tlbeing the actuating rod for ashplate 1' the rod 126 being extended, in the embodiment shown, throughpier or wall C. In Fig. 345 I have indicated by rrows the direction ormovement of the pistons in opening and closing the ash plate. In Fig. 30is shown the arrangement ofwater suppl pipes, the mainsupply pipe 270leading A slide valve 260 similar to liih Ill

from any suitable source of fluid pressure being provided with shut-offvalve 270. From pipe 270 leads a pipe 271 to cylinder 228, a manuallyadjustable regulating valve 271 being provided. Also leading from pipe270 is the pipe 27 2 having a manually operable valve 272 and a checkvalve 273, permitting flow of fluid in the direction indicated by thearrow in Fig. 30. In communication with the pipe 272 and extendingaround the valves 2"2 and 27 3 is the by-pass 274 having an adjustablerestricting valve, such as a needle valve 255, in the line.

The location of the exhaust ducts 225 225" and 226 and 2.26 is such thatair or steam will be entrapped as the pistons 233 and 263 approach theirlimits of travel, thus providing a cushioning means for the pistons.

In the operation of the mechanism just described, assuming thedimensions of the hydraulic and steam pistons to be proper for therelative pressures of steam and water,-

and piston 263 in the position shown in Fig. 34: at the beginning of theopening stroke, piston 263 Will move piston 26;) to the left forcing thewater or other fluid through. pipe 271 back into the supply pipe 270,the pressure of the steam and size of piston 263 being sufficient toovercome the force of the Water pressure upon piston 265. During thismovement slide valve 231 Will be moved to the left as viewed in Fi 33adi'nitting steam to the operative end of cylinder 225 and resulting inthe movement of piston 233 to the left with piston 235, Which Will forcethe water from cylinder 22? through. pipe 272, check valve 273permitting this flow. This movement of piston rod 234 results inmovement of the slide valve 260 to the right to cut off the supply ofsteam to and open exhaust from cylinder 226. After such out off, thepressure of the Water upon piston 265 Will move the latter and piston263 to the right, during which movement slide valve 231 is moved to outOh the supply of steam to and open the exhaust from cylinder 225. Afterthe exhaust from cylinder 225, the

ivater or other actuating fluid must flow through by-pass 274- tocylinder 22'1- this flow being comparatively slow, so that re ativelyconsiderable time will elapse before a sufficient volume of Water willenter cylinder 227 to move the piston 235 to the right to return valve260 to the position Which Will admit steam to the cylinder 226 to againopen the ash plate. Valve 271 may be adjusted to control the speed ofopening and closing of the ash plate by restricting the flow to and fromcylinder 228. Valve 2'72 can be adjusted to determine the length of thetime that the ash plate stays open. Valve 275 may be adjusted todetermine the length of time the dump plate stays closed. In this Wisecomparatively quick opening and closing of the ash plate may be effectedin the relatively long cycle during Which the plate is maintained inclosed position most of the time.

When it is desired to maintain the ash plate in a closed position avalve 230 in the steam line 230 must be closed and at the same time thecylinder 226 drained through the pet cock X, Fig. 34. When it is desiredto maintain the ash plate in open position valve 271 must be closed whenthe dump plate is in the open position and cylinder 228 must be drainedthrough pet cook Y, Fig. 34.

With the stokcr mechanism and structure described above, it will beapparent that I obtain the advantage resulting from the use of fixedtuyere bars and moving grate chains, as Well as the advantages of astationary grate in Which the leakage of draught air is impossible. Bymy construction the draught is obtained through the tuyere bars and thegrate chains to and through the body of fuel and as described above,short circuiting at the side or ends of the grate is substantiallyprecluded by means of the structure described. At the same timeprovision is made for the removal of ash and unburned fuel from thegrate and its deposit in the ash chute.

The provision of the stationary tuyere bars permit insertion of thesupporting blocl-is at the rear end of the stoker, thus providing aplurality of rigid anchored supports for the sealing aprons and tyingthe rear end sealing means to the stoker mechanism Which insures propercorrelation despite contraction and expansion of the stoker.

The checkered recesses upon the sealing plates serve to collect the ashor the like, which acts as a heat and Wear resistant. The plow membersand aprons, as Well as the kickers and casings, may be readily removedand replaced With minimum of inconvenience and expense.

The construction and operation of my invention is believed to besufliciently clear from the above description to enable those skilled inthe art to understand the same.

It will be obvious that my invention is susceptible to modification andI do not Wish to be restricted to the form shown and described, eXceptas defined in the appended claims.

lVhat I claim is- 1. In combination, a stoker mechanism comprisingalternately arranged moving grate chains and stationary tuyere bars,draught sealing means at the rear end of said stoker, said meanscomprising sealing members extending across the rear end of said stokerand overlying the same, and means extending forwardly of said sealingllO lit)

mem'be'rsin alinement with said tuyere'bars toret-ard the passage of ashand the like.

2.1n combination, a grate comprising spaced'endless gratechains,-supporting and moving means therefor, spaced transverse beams"at the rear portion of said grate, block members extending between andsecured to said beams in the spaces between said chains, an'd sealingaprons-carried by said block members at the rear endof-said grate.

3.111 combination, a stoker mechanism comprising alternately arrangedmoving grate chains, and stationary tuyere bars, draught sealing meansat the rear end of said stoker, said means comprising sealing membersextending across the rear end of said stoker and overlying the same, andmeans extending forwardly of said sealing members in alinementfiwithsaid tuyere bars to retard the passage of ash and the like, said lastnamed means being provided with movable members to 'assist in theremoval of accumulated ash.

4. 111 combination, -a stoker mechanism comprising alternately arrangedanoving grate chains and stationary tuyere bars, draught sealing meansat the rear end of said stoker, said means comprising sealing membersextending across the rear end of said stoker and overlying the same, andmeans extending forwardly of said sealing members in alinement with saidtuyere bars to retard the passage of ash and the like, said -'last namedmeans being provided with movable members to assist in the removal ofaccumulated ash, and 'means to actuate said movable members.

'5. In combination with a stoker comprisingendless chains, a sealingap-ron'overlying one end of saidstoker and having a. shoulder anda'bosslocated "forwardly thereof,-an ash diverting 'memberhaving an aperturedflange, s'aidflange being seatable-upon said shoulder of saidapron, saidboss fltting into said aperture.

In combination with a stokercomprising endless chains, a sealing apronoverlying one end of said 1 stokerand having a shoulder and a bosslocated "forwardly thereof, an ash diverting member having an aperturedflange, said flange being seatable upon said shoulder of said'apron,said {boss-fitting into said aperture, 's'aid -ash diverting memer"having a wedge-shaped body portion, and a shoulder at'the juncture'of'said flange and 'body portion.

7. In mechanism of the class described, a sealing apron'having ashoulderanda boss locatedforwardly thereof, a plow having an apertured flange,said flange being se'atable upon said slioulderof said apron, said'bossfitting into said aperture, said plow having a wedge-shapedbody port-ionsaid body pertion being provided with grooves increasing indepth fromrear to front.

8.111 combination, a stoker comprising endless moving spaced gratechains, supper ing blockslocatedbetween said chains, and sealing membersextending between and supported by saidblocks. I

9. In combination, a stoker comprising endless moving spaced gratechains, supportingblocks located between said chains, sealing membersextending between and supported by said bloc rs, and ash divertingmembers attached to and projecting forwardly of said sealing members,said ash diverting'members resting upon said chains.

10. In combination, a stoker comprising endless moving spaced gratechains, supporting blocks located between said chains, sealing membersextending between and supported by said blocks, and ash divertingmembers attached to and projecting for- 'wardly of said sealing members,said ash diverting members resting'upon said chains, and having theirupper surface located at an angle'to the plane of the surface of saidchain.

11. In mechanism of the class described, a stolrer comprising spacedendless moving grate chains, stationary bars located between saidchains, supporting blocks located between said chains adjacent the endsof said bars, sealing aprons extending-between and carried by saidsupporting blocks, plows extending forwardly of said aprons and coactingwith said chain grates to remove the ash therefrom, and'ash retardingmeans extending forwardly of said members between said chains and inline with said bars.

12. In mechanism of the class described, a stoker comprisingspaced'endless moving grate chains, stationary bars located between saidchains, supporting bloclrs located between said chains adjacent the endof said bars, sealing aprons extending between and carried by saidsupporting blocks, plows extending forwardly of said aprons and toacting with said chain-grates to remove the ash therefrom, and ashretarding means e2:- tending forwardly of said members between saidchains and'in line with said bars, said retardingmeans being providedwith means to assist i'n-the removal and discharge of ash.

'13. In combination with a supporting foundation, a stoker comprisingendless moving grate chains and means to regulate the draft adjacent therear end of said stolzer, said means comp ising fixed baffling meansextending downwardly from the upper run of said chains, and a coactingpivoted damper extending downwardly from the lower run of said chains tosaid foundation.

14. Iii-combination with a furnace having a combustion chamber and adraught ch'a1n her, a stolrer com rising endless moving grate chains, astationary baiiie extending from the upper runs of said chains, and apivotally mounted damper coacting with said battle to regulate the flowof draught air to one portion of said stoker, said pivotally mounteddamper being provided with a pivoted flap located adjacentthe bottom ofsaid draught chamber.

15. in combination with a furnace having a combustion chamber and adraught chamber, a stoker comprising endless moving grate chains, astationary battling means extendin from the upper runs of said chains,said baiiiing mea s being provided with apertures to accommodate thelower runs of said stolrer, and a pivoted damper coacting with saidbattling means to regulate the draft through one portion of said stoker.

16. In combination with a furnace having a. combustion chamber and adraught chamher, a stolrer comprising endless moving grate chains, astationary battle extending from the upper runs of said chains, apivot-- ally mounted damper coacting with said battle to regulate theflow of draught air to one portion of said Stoker chains, said pivotallymounted damper being provided with a pivoted fiap located adjacent thebottom of said draught damper, and means to operate said damper fromoutside said furnace.

17. In combination, a stolrer comprising alternating endless movinggrate chains and stationary bars, movable members located adjacent theends of said bars, said members being pivotally mounted, means toactuate said members comprising a rotatable shaft, and means tooperatively attacli'said shaft to said members.

18. In combination, a stoker comprising alternating endless moving gratechains and stationary bars, casings located adjacent the ends of saidbars extending between said chains, and ash disturbing members pivotallymounted in said casings.

19. In combination, a stoker comprising alternating endless moving gratechains and stationary bars, casings located adjacent the rear ends ofsaid bars extending between said chains and ash disturbing memberspivotally mounted in said casings, said casings being provided withinclined upper surfaces to normally retard the movement of ash thereoverfrom said bars.

20. In combination, a stoker comprising alternating endless moving gratechains and stationary bars, supporting blocks located. between saidchains at the rear end of said structure, casings mounted upon andsupported by said blocks forming a continuation of said bars. andi'novable members carried by said casings.

21. In combination a stolrer comprising alternating endless moving gratechains and stationary bars, supporting blocks located betweensaid chainsat the rear end of such structure, casings mounted upon and sup portedby said blocks forming a continuation of said bars, and movable memberscarried by said casings said blocks being provided with spaced platessupporting and located beneath the sides of said casings.

22. In combination, a stolrer comprising alternating endless movinggrate chains and stationary bars, supporting blocks located between saidchains at the rear end of such structure, casings mounted upon and supported by said blocks forn'iing a continuation of said bars, movablemembers carried by said casings, said blocks being provided with spacedplates supporting and located beneath the sides of said casings, and alever arm extending between the plates of each casing and operativelyattached to the corresponding ash disturbing member arried thereby.

23. In combination, a stoker comprising alternating endless grate chainsand intermediate tuyere bars, transverse supporting means at the rearend of said stoker, members extending between said chains at the rearends of said bars and provided with movable means to agitate or disturbash passing thereover, and ash diverting members alternating with saidextending members above said chains.

24:. In combination, a stoker comprising alternating endless gratechains and inter mediate tuyere bars, transverse supporting means at therear end of said stoker, members extending between said chains at therear ends of said bars and provided with movable means to agitate ordisturb ash passing thereover, ash diverting members alternating withsaid extending members above said chains, and sealing aprons overlyingthe rear end of said stoker and extending rearwardly from said extendingmembers and ash diverting members.

25. lln combination, a stoker comprising alternating endless gratechains and inter mediate tuyere bars, transverse supporting means at therear end of said stoker, members extending between said chains at therear ends of said bars and provided with movable means to agitate ordisturb ash passing thereover, ash diverting members alternating withsaid extending members above said chains, and sealing aprons overlyingthe rear end of said stoker and extending rearwardly from said extendingmembers and ash diverting members, supporting blocks on said transversesupporting means. and supporting said extending members and aprons.

26. In combination, a stokeicomprising alternating endless grate chainsand intermediate tuyere bars, transverse supporting lit)

